Tool for machining surfaces, edge areas and contours

ABSTRACT

The tool according to the invention has a variable loading of working means ( 3 - 6 ). The total set of working means ( 3 - 6 ) is divided into subsets, which, with respect to the direction of rotation ( 18 ), have different working angles ( 15, 16, 17 ). By changing the height ( 35 ) of subregions ( 23 - 28 ) of the base plate ( 1 ) of the tool, the free length of the working means ( 3 - 6 ) can also be varied. A single tool can be built, which combines several working functions and working properties in one tool. (FIG.  2 )

The invention relates to a tool for working surfaces, edge areas and contours, with a base plate rotating about a tool axis, a multiplicity of flexible working means, which are directed against a workpiece surface and fastened on a front face of the base plate, these working means being formed in the shape of rods and spaced apart from one another and the longitudinal axes of these working means forming a predetermined working angle with an imaginary axis at right angles to the front face of the base plate.

Tools of this type are known in many embodiments and serve inter alia for grinding, polishing and deburring of surfaces, edge areas and contours of workpieces produced by casting, pressing, punching or similar working processes. The workpieces are most often fastened on a workpiece carrier and the corresponding rotating tools are disposed on driving units, the workpiece carrier and driving units moving relative to one another.

A grinding tool of this type is known for example from EP 700 754 A1. In this tool on a disk-shaped and rotating base plate rod-shaped grinding means are disposed which are spaced apart in the radial direction as well as also in the direction of the circumference on the front face of the base plate. These grinding means are formed as working means and can have different shapes, for example the shape of a rod-form bundle or a rod with a grinding ball at the free end.

This publication also discloses placing the. working means, or grinding means, at right angles to the front face of the base plate or all of the working means at an incline with respect to the front face of the base plate. Between the longitudinal axis of an individual working means and of an imaginary axis at right angles to the front face of the base plate, a working angle is formed which has a defined relationship to the direction of the rotational movement. This known tool is utilized as a universal tool or in each instance is only equipped for a specific working case or a specific workpiece is equipped with suitable grinding means or working means. When exchanging the workpiece to be worked or the materials to be worked, a new tool must be equipped with suitable grinding or working means and the previous tool must be substituted. With complexly shaped workpieces it is often necessary to employ several tools in succession, and with each of the successive tools the working means are developed differently, in order to satisfy all requirements of the working sequence. This requires relatively expensive and elaborate driving units and high tool expenditures are generated since for a specific working sequence several different tools are required. High tool expenditures also become necessary since for a specific working sequence several different tools are required. When exchanging the workpieces to be worked, all tools must be adapted to the new working sequence and most often need to be exchanged. Exchanging the tools is often forgone with the consequence that the working process is no longer optimal. Complexly shaped parts can often only be inadequately worked. Moreover, tools of this type have the disadvantage that with unequal abrasion of the working or grinding means, it is necessary to exchange and dispose of the entire tool.

EP 983 825 A2 discloses an improved tool of this type, which is intended to be applied for deburring automobile wheel rims, in particular aluminum rims. This tool in the form of a head brush is equipped with a multiplicity of grinding bristle tufts, which form the working means. These grinding bristle tufts are secured in a base plate and directed approximately in the direction of the rotational axis against the workpiece to be worked. Some of the grinding bristle tufts are disposed at an incline with respect to the base plate, and specifically are inclined radially inwardly or outwardly. This disposition is made in particular in order to obtain a profiling of the working surface of the head brush. The described tool is suitable for working automobile wheel rims; however, in differently shaped workpieces it has similar disadvantages as already described above. Consequently, in complicated working sequences several successively disposed tools are here also necessary, which must be exchanged and newly optimized when changing over a workpiece.

The invention therefore addresses the problem of providing a tool with which surfaces, edge areas and contours, with simple as well as also complicated form can be optimally worked. With the same tool diverse working requirements are intended to be fulfilled such that several tools, disposed one behind the other, can be avoided or at least their number can be significantly reduced. Furthermore, subsets of the working means on the tool are to be exchangeable and replaceable in simple manner in order to make possible, for example, adaptations to diverse working sequences or to be able to replace abraded working means.

This problem is solved through the characteristics defined in patent claim 1. Advantageous further developments of the invention are evident on the basis of the characteristics of the dependent patent claims.

The core of the invention comprises that on a base plate of an inventive tool groups of working means are disposed which have diverse positions. For this purpose, their longitudinal axes, measured in the direction of the rotational movement, have different working angles between +60 and −60° This working angle is measured between the longitudinal axis of the particular working means and an imaginary axis at right angles to the front face of the base plate. The multiplicity or total number of the working means is divided into subsets or groups. At least a first subset of working means, and therewith their longitudinal axes, has a neutral working angle of 0°, and at least a second subset of working means, and therewith their longitudinal axes, has a positive working angle of up to +60°. With this basic configuration of the working means the two subsets can be mixed among each other or they can be disposed in two delimited regions of the base plate or they can be distributed over several delimited regions of the base plate. With this a universal tool can already be structured which is suitable for working a multiplicity of differently shaped workpieces. A further advantage results, if on the base plate at least a third subset of working means is disposed, the longitudinal axes of this group of working means being disposed at a negative working angle of up to −60°. With this advantageous disposition virtually all conceivable movement or working sequences of the working means can be effected. The individual subsets of working means can be comprised of different materials or they can have different dimensions or they are equipped with grinding means of different grain size or they have a combination of several such specifications. A further variation potentiality consists in forming the working means such they are flexible or at least partially rigid. This leads to further advantages in that on the same tool subsets of working means are disposed, which, with respect to the workpiece to be worked, have different working properties. This permits the optimization of the tool in terms of simple, but also of complicated, working sequences and working requirements. The variable loading of a single tool with different working means replaces several individual tools. Assigning the individual subsets of working means with different working angles to a specific region of the base plate, yields the advantage that equipping the base-plate with the working means is simplified. The base plate can be divided into several regions in the form of concentric rings or the base plate is divided into several regions in the form of sectors of a circle. To each of the regions of the ring or sectors is assigned one of the subsets of working means with a specific working angle. Especially advantageous is further the solution that the base plate is assembled of several structural parts and these structural parts are directly, or by means of a mounting plate, form-fittingly or force-fittingly connected with one another. The structural parts have therein the form of annuli, which are disposed concentrically and which form the entire base plate or they consist of sectors of a circle, which are also joined to form the complete base plate. This embodiment according to the invention entails the advantage that regions of the base plate or corresponding structural parts can be prefabricated and be equipped with working means in different configurations and formations. A standard set of annuli or sectors of a circle are provided with diverse placement of working means and, when needed, assembled to form a complete base plate with working means or to a tool. In this manner, in very short time and optimally, tools can be structured which can be adapted in optimal manner to the most diverse working processes and workpieces. It is no longer necessary in many cases to dispose several tools one after the other, but rather a single tool according to the invention can be assembled of several structural parts in universal manner. This leads to a tool which can be employed with greater versatility and to considerable savings of expenditures. Subsets of working means with more severe abrasion than the other subsets on the same tool can be replaced in simple manner without having to replace and dispose of the entire tool. It leads furthermore to additional advantages if at least one of the structural parts of an assembled tool has a different thickness. This thickness is measured in the direction of the tool axis. The free length of the working means can thereby be changed and therewith their bending behaviour. In this case on the same tool working means are available which have a different free length.

In the following the invention will be explained in further detail in conjunction with embodiment examples and with reference to the enclosed drawing. Therein depict:

FIG. 1 a perspective view of a tool according to the invention in simplified illustration with subsets of working means disposed in annuli,

FIG. 2 a perspective view of a tool according to the invention with subsets of working means disposed in sectors of a circle,

FIG. 3 a partial cross section through a working means with positive working angle,

FIG. 4 a partial cross section through a working means with neutral working angle, and

FIG. 5 a partial cross section through a working means with negative working angle.

FIG. 1 shows a tool according to the invention in simplified perspective representation. This tool comprises a base plate 1 with a drive shaft 29 and is rotatable about the tool axis 2. On the base plate 1 are fastened a multiplicity of working means 3-6. These working means 3-6 are in the form of rods and, with respect to the front face 11 of the base plate 1 as well as in the X and the Y direction, are disposed at a spacing from one another. The front face 11 of the base plate 1, and therewith the working means 3-6, are directed against a not shown workpiece to be worked. The entire set of working means 3-6, which is disposed on the base plate, is divided into subsets, with at least one first and one second subset of working means 3-6 available. The working means 3-6 of each of these subsets are disposed and/or formed differently. In the embodiment example according to FIG. 1 the front face 11 of the base plate 1 is divided into several regions in the form of concentric rings 19-22, and these rings 19-22 can only be imaginary or the base plate 1 can in reality be subdivided into annuli. The working means 3-6 in the described example are each comprised of a bristle tuft with a multiplicity of parallel bristles 28 as shown in FIG. 4. The individual bristles 28 of each bristle tuft are comprised of a suitable synthetic material known per se, which is equipped, in a manner also known per se, with a grinding means. However, it is also possible to utilize other suitable working means, such as are disclosed for example in EP 700 754 A1. In the depicted embodiment example the base plate 1 is effectively assembled from several structural parts in the form of annuli 19-22, and these annuli 19-22 are connected with one another through not shown connection and fastening means. To each of the annuli 19-22 a subset of working means 3-6 is assigned, which have a specific formation and a predetermined working angle.

The outermost annulus 22 is equipped with working means 3, which are disposed at right angles to the front face 11 of the base plate 1, as is shown in FIG. 4. The longitudinal axis 7 of each of the working means 3 extends congruently with an imaginary axis 12, which is at right angles to the front face 11 of the base plate 1. Therewith, the working means 3 are disposed at a neutral working angle of 0°. Within the scope of this description, by the term working angle 15, 16, 17 is understood an angle, which, viewed in the direction of the rotational movement, is formed between the longitudinal axes 7-10 of the working means 3-6 and imaginary axes 12, 13, 14. The imaginary axes 12, 13, 14 are at right angles to the front face 11 of the base plate 1 and extend through the intersection point of the longitudinal axes 7-10 of the working means 3-6 with the front face 11 of the base plate 1. If a working means 5 is inclined forwardly in the direction of the rotational movement, a positive working angle 15 is formed, as depicted in FIG. 3, and, if a working means 4 is inclined backwardly in the direction of the rotational movement 18, a negative working angle 16 is formed as depicted in FIG. 5. The negative working angles 16 can be in a range of 0 to −60° and the positive working angles in a range from 0 to +60°. In the depicted example according to FIGS. 1, 3 and 5, the negative working angles 16 are approximately −15° and the positive working angles 15 approximately +15°. The selection of the working angle 15, 16, 17 takes place as a function of the desired working effects on the workpiece to be worked or the surfaces, edge areas and contours on the workpiece.

The second concentric annulus 21 is equipped with working means 4, which are disposed at a negative working angle 16. This disposition is depicted in partial section in FIG. 5 in detail. The longitudinal axis 8, and therewith the working means 4, is inclined backwardly and a negative working angle 16 is formed with the imaginary axis 13. The next concentric annulus 20 is equipped with working means 5, which are inclined forwardly in the direction of the rotational movement 18. This disposition is depicted in FIG. 3 in partial section. The longitudinal axis 9, and therewith the working means 5, is inclined in the direction 18 of the rotational movement and the longitudinal axis 9 forms with the imaginary axis 14 a positive working angle 15. The next concentric annulus 19 is again equipped with working means 6, which are disposed in the same manner as the working means 3 on the outer annulus 22. The working means 6 are consequently also at right angles to the front face 11 of the base plate 1. When needed, further annuli can be disposed or, depending on the requirement of the working process, the working means 3-6 can be disposed at a different working angle. The working means 3-6 are, as shown in FIG. 3-5, secured in bores 30, 31 or 32 in the base plate 1 and are adhered by means of an adhesion agent 33, for example a two-component synthetic adhesive agent 33, with the base plate 1. However, the base plate 1 can also be formed in the shape of a pot or be formed with a margin. In this case the working means can be secured completely in a casting compound and this compound forms a portion of the base plate and fills the pot-like inner region. The disposition and positioning of the groups of working means in this casting compound in this case takes place with the aid of assembly devices. The division of the total set of working means 3-6 into at least two subsets, the working means associated with each subset having different working angles, permits realizing tools with optimal working properties. Since with the individual sets different piece numbers of working means 3-6 can be associated, an additional variation capability of the working properties results. It is furthermore possible, to impart to each of the subsets of working means 3-6 modified working properties through the additional change of material and form.

The tool according to the invention and depicted in FIG. 2 has the same characteristics and properties as the embodiment example according to FIG. 1. In the embodiment depicted in FIG. 2 the base plate 1′, or its front face 11′, is divided into several regions, which have the form of sectors of a circle. In the present case four sector regions were chosen, with each of which a subset of working means 3-6 is associated. The base plate 1′ is effectively assembled of four structural parts 23-26, which have the form of sectors of a circle. These four sectors 23-26 are disposed on a mounting plate 27 and are connected with it by means of securement means 34, for example machine screws. On the sector 23 are disposed working means 3, which have a neutral working angle of 0°. On sector 25 are also disposed the working means 6 in the same manner, i.e. the working means 3 and 6 are at right angles to the front face 11 of base plate 1′. However, the sector 23, measured in the direction of the tool axis 2, has a different, in this case, lesser, height 35 than the sector 25 and the two other sectors 24, 26. The working means 3 on the sector 23 have a greater free length than the working means 6 on the sector 25. This changes the flexibility or elasticity of the working means 3 and yields an additional variation capability. On the sector 24 are disposed working means 5, which have a positive working angle 15 of approximately 15°. They are consequently inclined forwardly in the direction 18 of the rotational movement. On circle sector 26 are disposed working means 4, which have a negative working angle 16. These working means 4 are consequently inclined backwardly with respect to the direction 18 of the rotational movement. In this embodiment example also further circle sectors with further subsets of working means can be disposed and/or the working means 3-6, due to a change of material or of form or of the working angle, have different working properties.

The embodiment according to FIG. 1, as well as also the embodiment according to FIG. 2, has the advantage that the base plate 1, or 1′, can be assembled in the manner of a mosaic of several structural parts 19-22 or 23-26, respectively. The discrete structural parts in the form of annuli 19-22 or of the circle sectors 23-26 can be prefabricated as single structural modules and be equipped differently with working means 3-6. The working means 3-6 have therein in particular different working angles, different materials, different grain sizes and/or different dimensions. It is thus possible to combine a tool according to the invention precisely to the requirements of the working process for a specific tool and therein to select individual annuli 19-22 or circle sectors 23-26, on which working means 3-6 of the suitable material, with the suitable dimensions, a suitable grinding means and an optimized working angle are disposed. The combination of the different subsets of working means 3-6 to form a total set of working means 3-6, which are disposed on the base plate 1, or 1′, respectively, permits an optimal adaptation to the working requirements. Furthermore, the tools of this type according to the invention can be combined simply and cost-effectively and, when needed, individual or several of the structural parts 19-22 or 23-26, respectively, can be exchanged. Adaptations to the working process can thereby be made without the entire tool needing to be changed every time. If individual regions of the total set of working means 3-6 show relatively severe abrasion, the dimensions of the structural parts 19-22 or 23-26, respectively, can be so selected that abraded regions can be replaced by new elements. This also permits the replacement of subsets of working means 3-6 which are abraded more severely than others, such that the entire tool can be utilized significantly longer than the solutions known up to now. However, a significant advantage of a tool according to the invention comprises that with a single tool with variable loadings, workings can be completed for which previously the use of several tools was necessary. 

1. Tool for working surfaces, edge areas and contours with a base plate (1) rotating about a tool axis (2), a multiplicity of flexible working means (3-6), which are directed against a workpiece surface and are fastened on the base plate (1), these working means (3-6) being formed in the shape of a rod and disposed at a spacing from each other, and the longitudinal axes (7-10) of these working means (3-6) forming a predetermined working angle (15, 16, 17) with an imaginary axis (12-14) at right angles to the front face (11) of the base plate (1), characterized in that the working angles (15, 16, 17) of the working means longitudinal axes (7-10), measured in the direction (18) of the rotational movement, are defined between +60° and −60° and therein a positive working angle is open in the forward direction in the direction of rotation (18) and a negative working angle is open toward the back against the direction of rotation (18), the multiplicity of the working means (3-6) are divided into subsets and in each subset the longitudinal axes (7-10) of the associated subset of working means (3-6) have a working angle (15, 16, 17) which differs from the working angle (15, 16, 17) of the other subsets, wherein at least one first subset of working means (3, 6), and therewith their longitudinal axes (7, 10) is disposed at a neutral working angle (17) of 0° and at least one second subset of working means (5), and therewith their longitudinal axes (9), is disposed at a positive working angle (15) of up to +60°.
 2. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that at least a third subset of working means (4) is fastened on the base plate (1), wherein their longitudinal axes (8) are disposed at a negative working angle (16) of up to −60°.
 3. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that each of the subsets of working means (3-6) with different working angles (15, 16, 17) is disposed in a certain region of the base plate.
 4. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that the base plate (1) is divided into several regions in the form of concentric rings (19-22) and with each of the ring regions (19-22) is associated one of the subsets of working means (3-6) with a certain working angle (15, 16, 17).
 5. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that the base plate (1) is divided into several regions in the form of circle sectors (23-26) and with each of the circle sectors (23-26) is associated one of the subsets of working means (3-6) with a certain working angle (15, 16, 17).
 6. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that the base plate (1; 1′) is assembled of several structural parts (19-22 or 23-26, respectively), these structural parts (19-22; 23-26) are connected with one another directly or by means of a mounting plate (27) form-fittingly and/or force-fittingly and these structural parts have the form of an annulus (19-22) or of a circle sector (23-26).
 7. Tool for working surfaces, edge areas and contours as claimed in claim 6, characterized in that the individual structural parts of the base plate (1; 1′) are each equipped with working means (3-6), which are disposed at a predetermined working angle (15, 16, 17) and therein at least two structural parts (19-22; 23-26) have working means (3-6) with different working angles (15, 16, 17).
 8. Tool for working surfaces, edge areas and contours as claimed in claim 6, characterized in that the individual structural parts (19-22; 23-26) have at least partially a different thickness in the direction of the tool axis (2).
 9. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that each of the working means (3-6) is comprised of a bristle tuft with a multiplicity of parallel bristles (28).
 10. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that the working means (3-6) of the individual subsets are comprised of diverse materials.
 11. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that the subsets of working means (3-6) are each equipped with grinding means of different grain size.
 12. Tool for working surfaces, edge areas and contours as claimed in claim 1, characterized in that each of the subsets of working means (3-6) has different dimensions. 